In recent years, along with high-definition images and the like, capacities of data to be transmitted between electronic devices have been significantly increasing, and communication methods in which large-capacity and high-speed data communication is possible are necessary. Wired optical communication using optical fibers is exemplified as a communication method in which such large-capacity and high-speed data communication can be implemented, and has already been commercialized in backbone system communication networks.
As wired optical communication using optical fibers described above, in high frequency communication in which large-capacity and high-speed data communication is possible, compared to low-speed communication methods, an influence on communication quality due to connection failure is large. Therefore, in wired optical communication in which large-capacity and high-speed data communication is possible, it is necessary to connect all optical fibers included in communication cables reliably without errors.